1. Field of the Invention
The present invention relates to a tyre comprising an electronic unit. Said invention also relates to a method of installing said electronic unit into said tyre.
2. Description of the Related Art
On some types of vehicles the necessity is felt to monitor the operating conditions of the tyres and to possibly keep traces of the evolution in time of some characteristic operating parameters. For instance, when vehicles using tyres of the run flat type are concerned, i.e. tyres capable of ensuring some kilometers of distance covered even in case of tyre deflation, provided some characteristic parameters are complied with such as maximum speed, temperature and maximum distance to be traveled over, the above requirement is particularly felt for safe use of said type of tyres.
The characteristic parameters that are generally considered may be identification code, temperature, pressure, distance run by the tyre, as well as parameters originating from mathematical calculations that can be carried out within the tyre or on board the vehicle.
To this aim, within the tyre an electronic unit can be mounted, said electronic unit being suitable for obtaining at least one of the above characteristic parameters. Preferably, the electronic unit can comprise at least one sensor, possibly associated with a control unit (such as a microprocessor) and/or a data storage unit and with an antenna; said antenna has the task of enabling radio-frequency signal exchange with the devices mounted on board the vehicle.
In addition, the antenna can allow the system present within the tyre to be suitably powered without using independent powering units (e.g. batteries within the tyre). Therefore, the apparatus mounted on board the vehicle are provided to generate an electromagnetic field with which the antenna placed in the tyre can be coupled by induction, and by virtue of which the necessary energy for operation of the sensor and the possible control unit is supplied by the antenna itself.
U.S. Pat. No. 5,090,237 proposes a pressure sensor for determining air pressure of a motor vehicle tyre; the sensor has a housing for extending into a recess formed in a rim wall of the tyre, and an annular flange located on the housing and supporting a spring against a side of the rim wall. The spring provides for clamping an outer flange portion of the pressure sensor housing against another side of the rim wall.